Replacement valve and anchor

ABSTRACT

Apparatus for endovascularly replacing a patient&#39;s heart valve, including: a replacement valve adapted to be delivered endovascularly to a vicinity of the heart valve; an expandable anchor adapted to be delivered endovascularly to the vicinity of the heart valve; and a lock mechanism configured to maintain a minimum amount of anchor expansion. The invention also includes a method for endovascularly replacing a patient&#39;s heart valve. In some embodiments the method includes the steps of: endovascularly delivering a replacement valve and an expandable anchor to a vicinity of the heart valve; expanding the anchor to a deployed configuration; and locking the anchor in the deployed configuration.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Ser. No. 15/842,426, filedDec. 14, 2017, which is a continuation of U.S. Ser. No. 15/842,306,filed Dec. 14, 2017, which is a continuation of U.S. Ser. No.15/675,978, filed Aug. 14, 2017, which is a continuation of Ser. No.14/147,902, filed Jan. 6, 2014 which is a Divisional application of Ser.No. 13/155,902, filed Jun. 8, 2011, now U.S. Pat. No. 8,623,078, whichis a Continuation application of Ser. No. 10/911,059, filed Aug. 3,2004, now U.S. Pat. 7,959,672, which is a Continuation application ofSer. No. 10/746,872, filed Dec. 23, 2003, now U.S. Pat. No. 8,182,528,the contents of each of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to methods and apparatus forendovascularly replacing a heart valve. More particularly, the presentinvention relates to methods and apparatus for endovascularly replacinga heart valve with a replacement valve using an expandable andretrievable anchor.

Heart valve surgery is used to repair or replace diseased heart valves.Valve surgery is an open-heart procedure conducted under generalanesthesia. An incision is made through the patient's sternum(sternotomy), and the patient's heart is stopped while blood flow isrerouted through a heart-lung bypass machine.

Valve replacement may be indicated when there is a narrowing of thenative heart valve, commonly referred to as stenosis, or when the nativevalve leaks or regurgitates. When replacing the valve, the native valveis excised and replaced with either a biologic or a mechanical valve.Mechanical valves require lifelong anticoagulant medication to preventblood clot formation, and clicking of the valve often may be heardthrough the chest. Biologic tissue valves typically do not require suchmedication. Tissue valves may be obtained from cadavers or may beporcine or bovine, and are commonly attached to synthetic rings that aresecured to the patient's heart.

Valve replacement surgery is a highly invasive operation withsignificant concomitant risk. Risks include bleeding, infection, stroke,heart attack, arrhythmia, renal failure, adverse reactions to theanesthesia medications, as well as sudden death. 2-5% of patients dieduring surgery.

Post-surgery, patients temporarily may be confused due to emboli andother factors associated with the heart-lung machine. The first 2-3 daysfollowing surgery are spent in an intensive care unit where heartfunctions can be closely monitored. The average hospital stay is between1 to 2 weeks, with several more weeks to months required for completerecovery.

In recent years, advancements in minimally invasive surgery andinterventional cardiology have encouraged some investigators to pursuepercutaneous replacement of the aortic heart valve. Percutaneous ValveTechnologies (“PVT”) of Fort Lee, N.J., has developed aballoon-expandable stent integrated with a bioprosthetic valve. Thestent/valve device is deployed across the native diseased valve topermanently hold the valve open, thereby alleviating a need to excisethe native valve and to position the bioprosthetic valve in place of thenative valve. PVT's device is designed for delivery in a cardiaccatheterization laboratory under local anesthesia using fluoroscopicguidance, thereby avoiding general anesthesia and open-heart surgery.The device was first implanted in a patient in April of 2002.

PVT's device suffers from several drawbacks. Deployment of PVT's stentis not reversible, and the stent is not retrievable. This is a criticaldrawback because improper positioning too far up towards the aorta risksblocking the coronary ostia of the patient. Furthermore, a misplacedstent/valve in the other direction (away from the aorta, closer to theventricle) will impinge on the mitral apparatus and eventually wearthrough the leaflet as the leaflet continuously rubs against the edge ofthe stent/valve.

Another drawback of the PVT device is its relatively largecross-sectional delivery profile. The PVT system's stent/valvecombination is mounted onto a delivery balloon, making retrogradedelivery through the aorta challenging. An antegrade transseptalapproach may therefore be needed, requiring puncture of the septum androuting through the mitral valve, which significantly increasescomplexity and risk of the procedure. Very few cardiologists arecurrently trained in performing a transseptal puncture, which is achallenging procedure by itself

Other prior art replacement heart valves use self-expanding stents asanchors. In the endovascular aortic valve replacement procedure,accurate placement of aortic valves relative to coronary ostia and themitral valve is critical. Standard self-expanding systems have very pooraccuracy in deployment, however. Often the proximal end of the stent isnot released from the delivery system until accurate placement isverified by fluoroscopy, and the stent typically jumps once released. Itis therefore often impossible to know where the ends of the stent willbe with respect to the native valve, the coronary ostia and the mitralvalve.

Also, visualization of the way the new valve is functioning prior tofinal deployment is very desirable. Visualization prior to final andirreversible deployment cannot be done with standard self-expandingsystems, however, and the replacement valve is often not fullyfunctional before final deployment.

Another drawback of prior art self-expanding replacement heart valvesystems is their lack of radial strength. In order for self-expandingsystems to be easily delivered through a delivery sheath, the metalneeds to flex and bend inside the delivery catheter without beingplastically deformed. In arterial stents, this is not a challenge, andthere are many commercial arterial stent systems that apply adequateradial force against the vessel wall and yet can collapse to a smallenough of a diameter to fit inside a delivery catheter withoutplastically deforming. However when the stent has a valve fastenedinside it, as is the case in aortic valve replacement, the anchoring ofthe stent to vessel walls is significantly challenged during diastole.The force to hold back arterial pressure and prevent blood from goingback inside the ventricle during diastole will be directly transferredto the stent/vessel wall interface. Therefore the amount of radial forcerequired to keep the self expanding stent/valve in contact with thevessel wall and not sliding will be much higher than in stents that donot have valves inside of them. Moreover, a self-expanding stent withoutsufficient radial force will end up dilating and contracting with eachheartbeat, thereby distorting the valve, affecting its function andpossibly migrating and dislodging completely. Simply increasing strutthickness of the self-expanding stent is not a practical solution as itruns the risk of larger profile and/or plastic deformation of theself-expanding stent.

U.S. patent application Serial No. 2002/0151970 to Garrison et al.describes a two-piece device for replacement of the aortic valve that isadapted for delivery through a patient's aorta. A stent isendovascularly placed across the native valve, then a replacement valveis positioned within the lumen of the stent. By separating the stent andthe valve during delivery, a profile of the device's delivery system maybe sufficiently reduced to allow aortic delivery without requiring atransseptal approach. Both the stent and a frame of the replacementvalve may be balloon-expandable or self-expanding.

While providing for an aortic approach, devices described in theGarrison patent application suffer from several drawbacks. First, thestent portion of the device is delivered across the native valve as asingle piece in a single step, which precludes dynamic repositioning ofthe stent during delivery. Stent foreshortening or migration duringexpansion may lead to improper alignment.

Additionally, Garrison's stent simply crushes the native valve leafletsagainst the heart wall and does not engage the leaflets in a manner thatwould provide positive registration of the device relative to the nativeposition of the valve. This increases an immediate risk of blocking thecoronary ostia, as well as a longer-term risk of migration of the devicepost-implantation. Further still, the stent comprises openings or gapsin which the replacement valve is seated post-delivery. Tissue mayprotrude through these gaps, thereby increasing a risk of improperseating of the valve within the stent.

In view of drawbacks associated with previously known techniques forendovascularly replacing a heart valve, it would be desirable to providemethods and apparatus that overcome those drawbacks.

SUMMARY OF THE INVENTION

One aspect of the invention provides an apparatus for endovascularlyreplacing a patient's heart valve, including: a replacement valveadapted to be delivered endovascularly to a vicinity of the heart valve;an expandable anchor adapted to be delivered endovascularly to thevicinity of the heart valve; and a lock mechanism configured to maintaina minimum amount of anchor expansion. The lock mechanism may includefirst and second mating interlocking elements. An actuator may beprovided to apply an actuation force on the anchor.

Another aspect of the invention provides a method for endovascularlyreplacing a patient's heart valve. In some embodiments the methodincludes the steps of: endovascularly delivering a replacement valve andan expandable anchor to a vicinity of the heart valve; expanding theanchor to a deployed configuration; and locking the anchor in thedeployed configuration.

Yet another aspect of the invention provides an apparatus forendovascularly replacing a patient's heart valve, including: an anchorcomprising a lip region and a skirt region; a replacement valve coupledto the anchor; and a lock, wherein the lip region and skirt region areconfigured for percutaneous expansion to engage the patient's heartvalve, and wherein the lock is configured to maintain such expansion.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIGS. 1A-B are elevational views of a replacement heart valve and anchoraccording to one embodiment of the invention.

FIGS. 2A-B are sectional views of the anchor and valve of FIGS. 1.

FIGS. 3A-B show delivery and deployment of a replacement heart valve andanchor, such as the anchor and valve of FIGS. 1 and 2.

FIGS. 4A-F also show delivery and deployment of a replacement heartvalve and anchor, such as the anchor and valve of FIGS. 1 and 2.

FIGS. 5A-F show the use of a replacement heart valve and anchor toreplace an aortic valve.

FIGS. 6A-F show the use of a replacement heart valve and anchor with apositive registration feature to replace an aortic valve.

FIG. 7 shows the use of a replacement heart valve and anchor with analternative positive registration feature to replace an aortic valve.

FIGS. 8A-C show another embodiment of a replacement heart valve andanchor according to the invention.

FIGS. 9A-H show delivery and deployment of the replacement heart valveand anchor of FIGS. 8.

FIG. 10 is a cross-sectional drawing of the delivery system used withthe method and apparatus of FIGS. 8 and 9.

FIGS. 11A-C show alternative locks for use with replacement heart valvesand anchors of this invention.

FIGS. 12A-C show a vessel wall engaging lock for use with replacementheart valves and anchors of this invention.

FIG. 13 demonstrates paravalvular leaking around a replacement heartvalve and anchor.

FIG. 14 shows a seal for use with a replacement heart valve and anchorof this invention.

FIGS. 15A-E show alternative arrangements of seals on a replacementheart valve and anchor.

FIGS. 16A-C show alternative seal designs for use with replacement heartvalves and anchors.

FIGS. 17A-B show an alternative anchor lock embodiment in an unlockedconfiguration.

FIGS. 18A-B show the anchor lock of FIGS. 17A-B in a lockedconfiguration.

FIG. 19 shows an alternative anchor deployment tool attachment andrelease mechanism for use with the invention.

FIG. 20 shows the attachment and release mechanism of FIG. 19 in theprocess of being released.

FIG. 21 shows the attachment and release mechanism of FIGS. 19 and 20 ina released condition.

FIG. 22 shows an alternative embodiment of a replacement heart valve andanchor and a deployment tool according to the invention in an undeployedconfiguration.

FIG. 23 shows the replacement heart valve and anchor of FIG. 22 in apartially deployed configuration.

FIG. 24 shows the replacement heart valve and anchor of FIGS. 22 and 23in a more fully deployed configuration but with the deployment toolstill attached.

FIG. 25 shows yet another embodiment of the delivery and deploymentapparatus of the invention in use with a replacement heart valve andanchor.

FIG. 26 shows the delivery and deployment apparatus of FIG. 25 in theprocess of deploying a replacement heart valve and anchor.

FIG. 27 show an embodiment of the invention employing seals at theinterface of the replacement heart valve and anchor and the patient'stissue.

FIG. 28 is a longitudinal cross-sectional view of the seal shown in FIG.27 in compressed form.

FIG. 29 is a transverse cross-sectional view of the seal shown in FIG.28.

FIG. 30 is a longitudinal cross-sectional view of the seal shown in FIG.27 in expanded form.

FIG. 31 is a transverse cross-sectional view of the seal shown in FIG.30.

FIG. 32 shows yet another embodiment of the replacement heart valve andanchor of this invention in an undeployed configuration.

FIG. 33 shows the replacement heart valve and anchor of FIG. 32 in adeployed configuration.

FIG. 34 shows the replacement heart valve and anchor of FIGS. 32 and 33deployed in a patient's heart valve.

FIGS. 35A-H show yet another embodiment of a replacement heart valve,anchor and deployment system according to this invention.

FIGS. 36A-E show more detail of the anchor of the embodiment shown inFIGS. 35A-H.

FIGS. 37A-B show other embodiments of the replacement heart valve andanchor of the invention.

FIGS. 38A-C illustrate a method for endovascularly replacing a patient'sdiseased heart valve.

DETAILED DESCRIPTION OF THE INVENTION

While preferred embodiments of the present invention have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the invention. It should be understoodthat various alternatives to the embodiments of the invention describedherein may be employed in practicing the invention. It is intended thatthe following claims define the scope of the invention and that methodsand structures within the scope of these claims and their equivalents becovered thereby.

With reference now to FIGS. 1-4, a first embodiment of replacement heartvalve apparatus in accordance with the present invention is described,including a method of actively foreshortening and expanding theapparatus from a delivery configuration and to a deployed configuration.Apparatus 10 comprises replacement valve 20 disposed within and coupledto anchor 30. FIG. 1 schematically illustrate individual cells of anchor30 of apparatus 10, and should be viewed as if the cylindrical anchorhas been cut open and laid flat. FIG. 2 schematically illustrate adetail portion of apparatus 10 in side-section.

Anchor 30 has a lip region 32, a skirt region 34 and a body region 36.First, second and third posts 38 a, 38 b and 38 c, respectively, arecoupled to skirt region 34 and extend within lumen 31 of anchor 30.Posts 38 preferably are spaced 120° apart from one another about thecircumference of anchor 30.

Anchor 30 preferably is fabricated by using self-expanding patterns(laser cut or chemically milled), braids and materials, such as astainless steel, nickel-titanium (“Nitinol”) or cobalt chromium butalternatively may be fabricated using balloon-expandable patterns wherethe anchor is designed to plastically deform to it's final shape bymeans of balloon expansion. Replacement valve 20 is preferably frombiologic tissues, e.g. porcine valve leaflets or bovine or equinepericardium tissues, alternatively it can be made from tissue engineeredmaterials (such as extracellular matrix material from Small IntestinalSubmucosa (SIS)) but alternatively may be prosthetic from an elastomericpolymer or silicone, Nitinol or stainless steel mesh or pattern(sputtered, chemically milled or laser cut). The leaflet may also bemade of a composite of the elastomeric or silicone materials and metalalloys or other fibers such Kevlar or carbon. Annular base 22 ofreplacement valve 20 preferably is coupled to skirt region 34 of anchor30, while commissures 24 of replacement valve leaflets 26 are coupled toposts 38.

Anchor 30 may be actuated using external non-hydraulic or non-pneumaticforce to actively foreshorten in order to increase its radial strength.As shown below, the proximal and distal end regions of anchor 30 may beactuated independently. The anchor and valve may be placed and expandedin order to visualize their location with respect to the native valveand other anatomical features and to visualize operation of the valve.The anchor and valve may thereafter be repositioned and even retrievedinto the delivery sheath or catheter. The apparatus may be delivered tothe vicinity of the patient's aortic valve in a retrograde approach in acatheter having a diameter no more than 23 french, preferably no morethan 21 french, more preferably no more than 19 french, or morepreferably no more than 17 french. Upon deployment the anchor andreplacement valve capture the native valve leaflets and positively lockto maintain configuration and position.

A deployment tool is used to actuate, reposition, lock and/or retrieveanchor 30. In order to avoid delivery of anchor 30 on a balloon forballoon expansion, a non-hydraulic or non-pneumatic anchor actuator isused. In this embodiment, the actuator is a deployment tool thatincludes distal region control wires 50, control rods or tubes 60 andproximal region control wires 62. Locks 40 include posts or arms 38preferably with male interlocking elements 44 extending from skirtregion 34 and mating female interlocking elements 42 in lip region 32.Male interlocking elements 44 have eyelets 45. Control wires 50 passfrom a delivery system for apparatus 10 through female interlockingelements 42, through eyelets 45 of male interlocking elements 44, andback through female interlocking elements 42, such that a double strandof wire 50 passes through each female interlocking element 42 formanipulation by a medical practitioner external to the patient toactuate and control the anchor by changing the anchor's shape. Controlwires 50 may comprise, for example, strands of suture.

Tubes 60 are reversibly coupled to apparatus 10 and may be used inconjunction with wires 50 to actuate anchor 30, e.g., to foreshorten andlock apparatus 10 in the fully deployed configuration. Tubes 60 alsofacilitate repositioning and retrieval of apparatus 10, as describedhereinafter. For example, anchor 30 may be foreshortened and radiallyexpanded by applying a distally directed force on tubes 60 whileproximally retracting wires 50. As seen in FIG. 3, control wires 62 passthrough interior lumens 61 of tubes 60. This ensures that tubes 60 arealigned properly with apparatus 10 during deployment and foreshortening.Control wires 62 can also actuate anchor 60; proximally directed forceson control wires 62 contacts the proximal lip region 32 of anchor 30.Wires 62 also act to couple and decouple tubes 60 from apparatus 10.Wires 62 may comprise, for example, strands of suture.

FIGS. 1A and 2A illustrate anchor 30 in a delivery configuration or in apartially deployed configuration (e.g., after dynamic self-expansionexpansion from a constrained delivery configuration within a deliverysheath). Anchor 30 has a relatively long length and a relatively smallwidth in the delivery or partially deployed configuration, as comparedto the foreshortened and fully deployed configuration of FIGS. 1B and2B.

In FIGS. 1A and 2A, replacement valve 20 is collapsed within lumen 31 ofanchor 30. Retraction of wires 50 relative to tubes 60 foreshortensanchor 30, which increases the anchor's width while decreasing itslength. Such foreshortening also properly seats replacement valve 20within lumen 31 of anchor 30. Imposed foreshortening will enhance radialforce applied by apparatus 10 to surrounding tissue over at least aportion of anchor 30. In some embodiments, the anchor exerts an outwardforce on surrounding tissue to engage the tissue in such way to preventmigration of anchor caused by force of blood against closed leafletduring diastole. This anchoring force is preferably 1 to 2 lbs, morepreferably 2 to 4 lbs, or more preferably 4 to 10 lbs. In otherembodiments, the anchoring force is preferably greater than 1 pound,more preferably greater than 2 pounds, or more preferably greater than 4pounds. Enhanced radial force of the anchor is also important forenhanced crush resistance of the anchor against the surrounding tissuedue to the healing response (fibrosis and contraction of annulus over alonger period of time) or to dynamic changes of pressure and flow ateach heart beat In an alternative embodiment, the anchor pattern orbraid is designed to have gaps or areas where the native tissue isallowed to protrude through the anchor slightly (not shown) and as theforeshortening is applied, the tissue is trapped in the anchor. Thisfeature would provide additional ‘means to prevent anchor migration andenhance long term stability of the device.

Deployment of apparatus 10 is fully reversible until lock 40 has beenlocked via mating of male interlocking elements 44 with femaleinterlocking elements 42. Deployment is then completed by decouplingtubes 60 from lip section 32 of anchor 30 by retracting one end of eachwire 62 relative to the other end of the wire, and by retracting one endof each wire 50 relative to the other end of the wire until each wirehas been removed from eyelet 45 of its corresponding male interlockingelement 44.

As best seen in FIG. 2B, body region 36 of anchor 30 optionally maycomprise barb elements 37 that protrude from anchor 30 in the fullydeployed configuration, for example, for engagement of a patient'snative valve leaflets and to preclude migration of the apparatus.

With reference now to FIG. 3, a delivery and deployment system for aself-expanding embodiment of apparatus 10 including a sheath 110 havinga lumen 112. Self-expanding anchor 30 is collapsible to a deliveryconfiguration within lumen 112 of sheath 110, such that apparatus 10 maybe delivered via delivery system 100. As seen in FIG. 3A, apparatus 10may be deployed from lumen 112 by retracting sheath 110 relative toapparatus 10, control wires 50 and tubes 60, which causes anchor 30 todynamically self-expand to a partially deployed configuration. Controlwires 50 then are retracted relative to apparatus 10 and tubes 60 toimpose foreshortening upon anchor 30, as seen in FIG. 3B.

During foreshortening, tubes 60 push against lip region 32 of anchor 30,while wires 50 pull on posts 38 of the anchor. Wires 62 may be retractedalong with wires 50 to enhance the distally-directed pushing forceapplied by tubes 60 to lip region 32. Continued retraction of wires 50relative to tubes 60 would lock locks 40 and fully deploy apparatus 10with replacement valve 20 properly seated within anchor 30, as in FIGS.1B and 2B. Apparatus 10 comprises enhanced radial strength in the fullydeployed configuration as compared to the partially deployedconfiguration of FIG. 3A. Once apparatus 10 has been fully deployed,wires 50 and 62 may be removed from apparatus 10, thereby separatingdelivery system 100 and tubes 60 from the apparatus.

Deployment of apparatus 10 is fully reversible until locks 40 have beenactuated. For example, just prior to locking the position of the anchorand valve and the operation of the valve may be observed underfluoroscopy. If the position needs to be changed, by alternatelyrelaxing and reapplying the proximally directed forces exerted bycontrol wires 50 and/or control wires 62 and the distally directedforces exerted by tubes 60, expansion and contraction of the lip andskirt regions of anchor 30 may be independently controlled so that theanchor and valve can be moved to, e.g., avoid blocking the coronaryostia or impinging on the mitral valve. Apparatus 10 may also becompletely retrieved within lumen 112 of sheath 110 by simultaneouslyproximally retracting wires 50 and tubes 60/wires 62 relative to sheath110. Apparatus 10 then may be removed from the patient or repositionedfor subsequent redeployment.

Referring now to FIGS. 4, step-by-step deployment of apparatus 10 viadelivery system 100 is described. In FIG. 4A, sheath 110 is retractedrelative to apparatus 10, wires 50 and tubes 60, thereby causingself-expandable anchor 30 to dynamically self-expand apparatus 10 fromthe collapsed delivery configuration within lumen 112 of sheath 110 tothe partially deployed configuration. Apparatus 10 may then bedynamically repositioned via tubes 60 to properly orient the apparatus,e.g. relative to a patient's native valve leaflets.

In FIG. 4B, control wires 50 are retracted while tubes 60 are advanced,thereby urging lip region 32 of anchor 30 in a distal direction whileurging posts 38 of the anchor in a proximal direction. This foreshortensapparatus 10, as seen in FIG. 4C. Deployment of apparatus 10 is fullyreversible even after foreshortening has been initiated and has advancedto the point illustrated in FIG. 4C.

In FIG. 4D, continued foreshortening causes male interlocking elements44 of locks 40 to engage female interlocking elements 42. The maleelements mate with the female elements, thereby locking apparatus 10 inthe foreshortened configuration, as seen in FIG. 4E. Wires 50 are thenpulled through eyelets 45 of male elements 44 to remove the wires fromapparatus 10, and wires 62 are pulled through the proximal end of anchor30 to uncouple tubes 60 from the apparatus, thereby separating deliverysystem 100 from apparatus 10. Fully deployed apparatus 10 is shown inFIG. 4F.

Referring to FIGS. 5, a method of endovascularly replacing a patient'sdiseased aortic valve with apparatus 10 and delivery system 100 isdescribed. As seen in Figure SA, sheath 110 of delivery system 100,having apparatus 10 disposed therein, is endovascularly advanced overguide wire G, preferably in a retrograde fashion (although an antegradeor hybrid approach alternatively may be used), through a patient's aortaA to the patient's diseased aortic valve AV. A nosecone 102 precedessheath 110 in a known manner. In FIG. 5B, sheath 110 is positioned suchthat its distal region is disposed within left ventricle LV of thepatient's heart H.

Apparatus 10 is deployed from lumen 112 of sheath 110, for example,under fluoroscopic guidance, such that anchor 30 of apparatus 10dynamically self-expands to a partially deployed configuration, as inFIG. 5C. Advantageously, apparatus 10 may be retracted within lumen 112of sheath 110 via wires 50—even after anchor 30 has dynamically expandedto the partially deployed configuration, for example, to abort theprocedure or to reposition apparatus 10 or delivery system 100. As yetanother advantage, apparatus 10 may be dynamically repositioned, e.g.via sheath 110 and/or tubes 60, in order to properly align the apparatusrelative to anatomical landmarks, such as the patient's coronary ostiaor the patient's native valve leaflets L. When properly aligned, skirtregion 34 of anchor 30 preferably is disposed distal of the leaflets,while body region 36 is disposed across the leaflets and lip region 32is disposed proximal of the leaflets.

Once properly aligned, wires 50 are retracted relative to tubes 60 toimpose foreshortening upon anchor 30 and expand apparatus 10 to thefully deployed configuration, as in FIG. 5D. Foreshortening increasesthe radial strength of anchor 30 to ensure prolonged patency of valveannulus An, as well as to provide a better seal for apparatus 10 thatreduces paravalvular regurgitation. As seen in FIG. 5E, locks 40maintain imposed foreshortening. Replacement valve 20 is properly seatedwithin anchor 30, and normal blood flow between left ventricle LV andaorta A is thereafter regulated by apparatus 10. Deployment of apparatus10 advantageously is fully reversible until locks 40 have been actuated.

As seen in FIG. 5F, wires 50 are pulled from eyelets 45 of male elements44 of locks 40, tubes 60 are decoupled from anchor 30, e.g. via wires62, and delivery system 100 is removed from the patient, therebycompleting deployment of apparatus 10. Optional barb elements 37 engagethe patient's native valve leaflets, e.g. to preclude migration of theapparatus and/or reduce paravalvular regurgitation.

With reference now to FIGS. 6, a method of endovascularly replacing apatient's diseased aortic valve with apparatus 10 is provided, whereinproper positioning of the apparatus is ensured via positive registrationof a modified delivery system to the patient's native valve leaflets. InFIG. 6A, modified delivery system 100′ delivers apparatus 10 to diseasedaortic valve AV within sheath 110. As seen in FIGS. 6B and 6C, apparatus10 is deployed from lumen 112 of sheath 110, for example, underfluoroscopic guidance, such that anchor 30 of apparatus 10 dynamicallyself-expands to a partially deployed configuration. As when deployed viadelivery system 100, deployment of apparatus 10 via delivery system 100′is fully reversible until locks 40 have been actuated.

Delivery system 100′ comprises leaflet engagement element 120, whichpreferably self-expands along with anchor 30. Engagement element 120 isdisposed between tubes 60 of delivery system 100′ and lip region 32 ofanchor 30. Element 120 releasably engages the anchor. As seen in FIG.6C, the element is initially deployed proximal of the patient's nativevalve leaflets L. Apparatus 10 and element 120 then may beadvanced/dynamically repositioned until engagement element positivelyregisters against the leaflets, thereby ensuring proper positioning ofapparatus 10. Also delivery system 100′ includes filter structure 61A(e.g., filter membrane or braid) as part of push tubes 60 to act as anembolic protection element. Emboli can be generated during manipulationand placement of anchor from either diseased native leaflet orsurrounding aortic tissue and can cause blockage. Arrows 61B in FIG. 6Eshow blood flow through filter structure 61A where blood is allowed toflow but emboli is trapped in the delivery system and removed with it atthe end of the procedure.

Alternatively, foreshortening may be imposed upon anchor 30 whileelement 120 is disposed proximal of the leaflets, as in FIG. 6D. Uponpositive registration of element 120 against leaflets L, element 120precludes further distal migration of apparatus 10 during additionalforeshortening, thereby reducing a risk of improperly positioning theapparatus. FIG. 6E details engagement of element 120 against the nativeleaflets. As seen in FIG. 6F, once apparatus 10 is fully deployed,element 120, wires 50 and tubes 60 are decoupled from the apparatus, anddelivery system 100′ is removed from the patient, thereby completing theprocedure.

With reference to FIG. 7, an alternative embodiment of the apparatus ofFIGS. 6 is described, wherein leaflet engagement element 120 is coupledto anchor 30 of apparatus 10′, rather than to delivery system 100.Engagement element 120 remains implanted in the patient post-deploymentof apparatus 10′. Leaflets L are sandwiched between lip region 32 ofanchor 30 and element 120 in the fully deployed configuration. In thismanner, element 120 positively registers apparatus 10′ relative to theleaflets and precludes distal migration of the apparatus over time.

Referring now to FIGS. 8, an alternative delivery system adapted for usewith a balloon expandable embodiment of the present invention isdescribed. In FIG. 8A, apparatus 10″ comprises anchor 30′ that may befabricated from balloon-expandable materials. Delivery system 100″comprises inflatable member 130 disposed in a deflated configurationwithin lumen 31 of anchor 30′. In FIG. 8B, optional outer sheath 110 isretracted, and inflatable member 130 is inflated to expand anchor 30′ tothe fully deployed configuration. As inflatable member 130 is beingdeflated, as in earlier embodiments, wires 50 and 62 and tubes 60 may beused to assist deployment of anchor 30′ and actuation of locks 40, aswell as to provide reversibility and retrievability of apparatus 10″prior to actuation of locks 40. Next, wires 50 and 62 and tubes 60 areremoved from apparatus 10″, and delivery system 100″ is removed, as seenin FIG. 8C.

As an alternative delivery method, anchor 30′ may be partially deployedvia partial expansion of inflatable member 130. The inflatable memberwould then be advanced within replacement valve 20 prior to inflation ofinflatable member 130 and full deployment of apparatus 10″. Inflationpressures used will range from about 3 to 6 atm, or more preferably fromabout 4 to 5 atm, though higher and lower atm pressures may also be used(e.g., greater than 3 atm, more preferably greater than 4 atm, morepreferably greater than 5 atm, or more preferably greater than 6 atm).Advantageously, separation of inflatable member 130 from replacementvalve 20, until partial deployment of apparatus 10″ at a treatment site,is expected to reduce a delivery profile of the apparatus, as comparedto previously known apparatus. This profile reduction may facilitateretrograde delivery and deployment of apparatus 10″, even when anchor30′ is balloon-expandable.

Although anchor 30′ has illustratively been described as fabricated fromballoon-expandable materials, it should be understood that anchor 30′alternatively may be fabricated from self-expanding materials whoseexpansion optionally may be balloon-assisted. In such a configuration,anchor 30′ would expand to a partially deployed configuration uponremoval of outer sheath 110. If required, inflatable member 130 thenwould be advanced within replacement valve 20 prior to inflation.Inflatable member 130 would assist full deployment of apparatus 10″, forexample, when the radial force required to overcome resistance fromimpinging tissue were too great to be overcome simply by manipulation ofwires 50 and tubes 60. Advantageously, optional placement of inflatablemember 130 within replacement valve 20, only after dynamicself-expansion of apparatus 10″ to the partially deployed configurationat a treatment site, is expected to reduce a delivery profile of theapparatus, as compared to previously known apparatus. This reduction mayfacilitate retrograde delivery and deployment of apparatus 10″.

With reference to FIGS. 9 and 10, methods and apparatus for aballoon-assisted embodiment of the present invention are described ingreater detail. FIGS. 9 and 10 illustratively show apparatus 10′ ofFIGS. 7 used in combination with delivery system 100″ of FIGS. 8. FIG.10 illustrates a sectional view of delivery system 100″. Inner shaft 132of inflatable member 130 preferably is about 4 Fr in diameter, andcomprises lumen 133 configured for passage of guidewire G, having adiameter of about 0.035″, therethrough. Push tubes 60 and pull wires 50pass through guidetube 140, which preferably has a diameter of about 15Fr or smaller. Guide tube 140 is disposed within lumen 112 of outersheath 110, which preferably has a diameter of about 17 Fr or smaller.

In FIG. 9A, apparatus 10′ is delivered to diseased aortic valve AVwithin lumen 112 of sheath 110. In FIG. 9B, sheath 110 is retractedrelative to apparatus 10′ to dynamically self-expand the apparatus tothe partially deployed configuration. Also retracted and removed isnosecone 102 which is attached to a pre-slit lumen (not shown) thatfacilitates its removal prior to loading and advancing of a regularangioplasty balloon catheter over guidewire and inside delivery system110.

In FIG. 9C, pull wires 50 and push tubes 60 are manipulated fromexternal to the patient to foreshorten anchor 30 and sufficiently expandlumen 31 of the anchor to facilitate advancement of inflatable member130 within replacement valve 20. Also shown is the tip of an angioplastycatheter 130 being advanced through delivery system 110.

The angioplasty balloon catheter or inflatable member 130 then isadvanced within the replacement valve, as in FIG. 9D, and additionalforeshortening is imposed upon anchor 30 to actuate locks 40, as in FIG.9E. The inflatable member is inflated to further displace the patient'snative valve leaflets L and ensure adequate blood flow through, andlong-term patency of, replacement valve 20, as in FIG. 9F. Inflatablemember 130 then is deflated and removed from the patient, as in FIG. 9G.A differentsize angioplasty balloon catheter could be used to repeat thesame step if deemed necessary by the user. Push tubes 60 optionally maybe used to further set leaflet engagement element 120, or optional barbsB along posts 38, more deeply within leaflets L, as in FIG. 9H. Then,delivery system 100″ is removed from the patient, thereby completingpercutaneous heart valve replacement.

As will be apparent to those of skill in the art, the order of imposedforeshortening and balloon expansion described in FIGS. 9 and 10 is onlyprovided for the sake of illustration. The actual order may varyaccording to the needs of a given patient and/or the preferences of agiven medical practitioner. Furthermore, balloon-assist may not berequired in all instances, and the inflatable member may act merely as asafety precaution employed selectively in challenging clinical cases.

Referring now to FIGS. 11, alternative locks for use with apparatus ofthe present invention are described. In FIG. 11A, lock 40′ comprisesmale interlocking element 44 as described previously. However, femaleinterlocking element 42′ illustratively comprises a triangular shape, ascompared to the round shape of interlocking element 42 describedpreviously. The triangular shape of female interlocking element 42′ mayfacilitate mating of male interlocking element 44 with the femaleinterlocking element without necessitating deformation of the maleinterlocking element.

In FIG. 11B, lock 40″ comprises alternative male interlocking element44′ having multiple in-line arrowheads 46 along posts 38. Each arrowheadcomprises resiliently deformable appendages 48 to facilitate passagethrough female interlocking element 42. Appendages 48 optionallycomprise eyelets 49, such that control wire 50 or a secondary wire maypass therethrough to constrain the appendages in the deformedconfiguration. To actuate lock 40″, one or more arrowheads 46 of maleinterlocking element 44′ are drawn through female interlocking element42, and the wire is removed from eyelets 49, thereby causing appendages48 to resiliently expand and actuate lock 40″.

Advantageously, providing multiple arrowheads 46 along posts 38 yields aratchet that facilitates in-vivo determination of a degree offoreshortening imposed upon apparatus of the present invention.Furthermore, optionally constraining appendages 48 of arrowheads 46 viaeyelets 49 prevents actuation of lock 40″ (and thus deployment ofapparatus of the present invention) even after male element 44′ has beenadvanced through female element 42. Only after a medical practitionerhas removed the wire constraining appendages 48 is lock 40″ fullyengaged and deployment no longer reversible.

Lock 40′″ of FIG. 11C is similar to lock 40″ of FIG. 11B, except thatoptional eyelets 49 on appendages 48 have been replaced by optionalovertube 47. Overtube 47 serves a similar function to eyelets 49 byconstraining appendages 48 to prevent locking until a medicalpractitioner has determined that apparatus of the present invention hasbeen foreshortened and positioned adequately at a treatment site.Overtube 47 is then removed, which causes the appendages to resilientlyexpand, thereby fully actuating lock 40′″.

With reference to FIGS. 12, an alternative locking mechanism isdescribed that is configured to engage the patient's aorta. Maleinterlocking elements 44″ of locks 40″″ comprise arrowheads 46′ havingsharpened appendages 48′. Upon expansion from the delivery configurationof FIG. 12A to the foreshortened configuration of FIG. 12B, apparatus 10positions sharpened appendages 48′ adjacent the patient's aorta A.Appendages 48′ engage the aortic wall and reduce a risk of devicemigration over time.

With reference now to FIG. 13, a risk of paravalvular leakage orregurgitation around apparatus of the present invention is described. InFIG. 13, apparatus 10 has been implanted at the site of diseased aorticvalve AV, for example, using techniques described hereinabove. Thesurface of native valve leaflets L is irregular, and interface I betweenleaflets Land anchor 30 may comprise gaps where blood B may seepthrough. Such leakage poses a risk of blood clot formation orinsufficient blood flow.

Referring to FIG. 14, optional elements for reducing regurgitation orleakage are described. Compliant sacs 200 may be disposed about theexterior of anchor 30 to provide a more efficient seal along irregularinterface I. Sacs 200 may be filled with an appropriate material, forexample, water, blood, foam or a hydrogel. Alternative fill materialswill be apparent.

With reference to FIGS. 15, illustrative arrangements for sacs 200 areprovided. In FIG. 15A, sacs 200 are provided as discrete sacs atdifferent positions along the height of anchor 30. In FIG. 15B, the sacsare provided as continuous cylinders at various heights. In FIG. 15C, asingle sac is provided with a cylindrical shape that spans multipleheights. The sacs of FIG. 15D are discrete, smaller and provided inlarger quantities. FIG. 15E provides a spiral sac. Alternative sacconfigurations will be apparent to those of skill in the art.

With reference to FIGS. 16, exemplary techniques for fabricating sacs200 are provided. In FIG. 16A, sacs 20 comprise ‘fish-scale’ slots 202that may be back-filled, for example, with ambient blood passing throughreplacement valve 20. In FIG. 16B, the sacs comprise pores 204 that maybe used to fill the sacs. In FIG. 16C, the sacs open to lumen 31 ofanchor 30 and are filled by blood washing past the sacs as the bloodmoves through apparatus 10.

FIGS. 17A-B and 18A-B show yet another alternative embodiment of theanchor lock. Anchor 300 has a plurality of male interlocking elements302 having eyelets 304 formed therein. Male interlocking elements areconnected to braided structure 300 by inter-weaving elements 302 (and308) or alternatively suturing, soldering, welding, or connecting withadhesive. Valve commissures 24 are connected to male interlockingelements 302 along their length. Replacement valve 20 annular base 22 isconnected to the distal end 34 of anchor 300 (or 30) as is illustratedin FIGS. 1A and 1B. Male interlocking elements 302 also include holes306 that mate with tabs 310 extending into holes 312 in femaleinterlocking elements 308. To lock, control wires 314 passing througheyelets 304 and holes 312 are pulled proximally with respect to theproximal end of braided anchor 300 to draw the male interlockingelements through holes 312 so that tabs 310 engage holes 306 in maleinterlocking elements 302. Also shown is release wires 314B that passesthrough eyelet 304B in female interlocking element 308. If needed,during the procedure, the user may pull on release wires 314B reversingorientation of tabs 310 releasing the anchor and allowing forrepositioning of the device or it's removal from the patient. Only whenfinal positioning as desired by the operating physician, would releasewire 314B and control wire 314 are cut and removed from the patient withthe delivery system.

FIGS. 19-21 show an alternative way of releasing the connection betweenthe anchor and its actuating tubes and control wires. Control wires 62extend through tubes 60 from outside the patient, loop through theproximal region of anchor 30 and extend partially back into tube 60. Thedoubled up portion of control wire 62 creates a force fit within tube 60that maintains the control wire's position with respect to tube 60 whenall control wires 62 are pulled proximally to place a proximallydirected force on anchor 30. When a single control wire 62 is pulledproximally, however, the frictional fit between that control wire andthe tube in which it is disposed is overcome, enabling the end 63 ofcontrol wire 62 to pull free of the tube, as shown in FIG. 21, therebyreleasing anchor 30.

FIGS. 22-24 show an alternative embodiment of the anchor. Anchor 350 ismade of a metal braid, such as Nitinol or stainless steel. A replacementvalve 354 is disposed within anchor 350. Anchor 350 is actuated insubstantially the same way as anchor 30 of FIGS. 1-4 through theapplication of proximally and distally directed forces from controlwires (not shown) and tubes 352.

FIGS. 25 and 26 show yet another embodiment of the delivery anddeployment apparatus of the invention. As an alternative to the balloonexpansion method described with respect to FIGS. 8, in this embodimentthe nosecone (e.g., element 102 of FIGS. 5) is replaced by anangioplasty balloon catheter 360. Thus, angioplasty balloon catheter 360precedes sheath 110 on guidewire G. When anchor 30 and valve 20 areexpanded through the operation of tubes 60 and the control wires (notshown) as described above, balloon catheter 360 is retracted proximallywithin the expanded anchor and valve and expanded further as describedabove with respect to FIGS. 8.

FIGS. 27-31 show seals 370 that expand over time to seal the interfacebetween the anchor and valve and the patient's tissue. Seals 370 arepreferably formed from Nitinol wire surrounded by an expandable foam. Asshown in cross-section in FIGS. 28 and 29, at the time of deployment,the foam 372 is compressed about the wire 374 and held in the compressedform by a time-released coating 376. After deployment, coating 376dissolves in vivo to allow foam 372 to expand, as shown in FIGS. 30 and31.

FIGS. 32-34 show another way to seal the replacement valve againstleakage. A fabric seal 380 extends from the distal end of valve 20 andback proximally over anchor 30 during delivery. When deployed, as shownin FIGS. 33 and 34, fabric seal 380 bunches up to create fabric flapsand pockets that extend into spaces formed by the native valve leaflets382, particularly when the pockets are filled with blood in response tobackflow blood pressure. This arrangement creates a seal around thereplacement valve.

FIGS. 35A-H show another embodiment of a replacement heart valveapparatus in accordance with the present invention. Apparatus 450comprises replacement valve 460 (see FIGS. 37B and 38C) disposed withinand coupled to anchor 470. Replacement valve 460 is preferably biologic,e.g. porcine, but alternatively may be synthetic. Anchor 470 preferablyis fabricated from self-expanding materials, such as a stainless steelwire mesh or a nickel-titanium alloy (“Nitinol”), and comprises lipregion 472, skirt region 474, and body regions 476 a, 476 b and 476 c.Replacement valve 460 preferably is coupled to skirt region 474, butalternatively may be coupled to other regions of the anchor. Asdescribed hereinbelow, lip region 472 and skirt region 474 areconfigured to expand and engage/capture a patient's native valveleaflets, thereby providing positive registration, reducing paravalvularregurgitation, reducing device migration, etc.

As seen in FIG. 35A, apparatus 450 is collapsible to a deliveryconfiguration, wherein the apparatus may be delivered via deliverysystem 410. Delivery system 410 comprises sheath 420 having lumen 422,as well as wires 424 a and 424 b seen in FIGS. 35D-35G. Wires 424 a areconfigured to expand skirt region 474 of anchor 470, as well asreplacement valve 460 coupled thereto, while wires 424 b are configuredto expand lip region 472.

As seen in FIG. 35B, apparatus 450 may be delivered and deployed fromlumen 422 of catheter 420 while the apparatus is disposed in thecollapsed delivery configuration. As seen in FIGS. 35B-35D, catheter 420is retracted relative to apparatus 450, which causes anchor 470 todynamically self-expand to a partially deployed configuration. Wires 424a are then retracted to expand skirt region 474, as seen in FIGS. 35Eand 35F. Preferably, such expansion may be maintained via lockingfeatures described hereinafter.

In FIG. 35G, wires 424 b are retracted to expand lip region 472 andfully deploy apparatus 450. As with skirt region 474, expansion of lipregion 472 preferably may be maintained via locking features. After bothlip region 472 and skirt region 474 have been expanded, wires 424 may beremoved from apparatus 450, thereby separating delivery system 410 fromthe apparatus. Delivery system 410 then may be removed, as seen in FIG.35H.

As will be apparent to those of skill in the art, lip region 472optionally may be expanded prior to expansion of skirt region 474. Asyet another alternative, lip region 472 and skirt region 474 optionallymay be expanded simultaneously, in parallel, in a step-wise fashion orsequentially. Advantageously, delivery of apparatus 450 is fullyreversible until lip region 472 or skirt region 474 has been locked inthe expanded configuration.

With reference now to FIGS. 36A-E, individual cells of anchor 470 ofapparatus 450 are described to detail deployment and expansion of theapparatus. In FIG. 36A, individual cells of lip region 472, skirt region474 and body regions 476 a, 476 b and 476 c are shown in the collapseddelivery configuration, as they would appear while disposed within lumen422 of sheath 420 of delivery system 410 of FIGS. 35. A portion of thecells forming body regions 476, for example, every ‘nth’ row of cells,comprises locking features.

Body region 476 a comprises male interlocking element 482 of lip lock480, while body region 476 b comprises female interlocking element 484of lip lock 480. Male element 482 comprises eyelet 483. Wire 424 bpasses from female interlocking element 484 through eyelet 483 and backthrough female interlocking element 484, such that there is a doublestrand of wire 424 b that passes through lumen 422 of catheter 420 formanipulation by a medical practitioner external to the patient. Bodyregion 476 b further comprises male interlocking element 492 of skirtlock 490, while body region 476 c comprises female interlocking element494 of the skirt lock. Wire 424 a passes from female interlockingelement 494 through eyelet 493 of male interlocking element 492, andback through female interlocking element 494. Lip lock 480 is configuredto maintain expansion of lip region 472, while skirt lock 490 isconfigured to maintain expansion of skirt region 474.

In FIG. 36B, anchor 470 is shown in the partially deployedconfiguration, e.g., after deployment from lumen 422 of sheath 420. Bodyregions 476, as well as lip region 472 and skirt region 474, self-expandto the partially deployed configuration. Full deployment is thenachieved by retracting wires 424 relative to anchor 470, and expandinglip region 472 and skirt region 474 outward, as seen in FIGS. 36C and36D. As seen in FIG. 36E, expansion continues until the male elementsengage the female interlocking elements of lip lock 480 and skirt lock490, thereby maintaining such expansion (lip lock 480 shown in FIG.36E). Advantageously, deployment of apparatus 450 is fully reversibleuntil lip lock 480 and/or skirt lock 490 has been actuated.

With reference to FIGS. 37A-B, isometric views, partially in section,further illustrate apparatus 450 in the fully deployed and expandedconfiguration. FIG. 37A illustrates the wireframe structure of anchor470, while FIG. 37B illustrates an embodiment of anchor 470 covered in abiocompatible material B. Placement of replacement valve 460 withinapparatus 450 may be seen in FIG. 37B. The patient's native valve iscaptured between lip region 472 and skirt region 474 of anchor 470 inthe fully deployed configuration (see FIG. 38B).

Referring to FIGS. 38A-C, in conjunction with FIGS. 35 and 36, a methodfor endovascularly replacing a patient's diseased aortic valve withapparatus 450 is described. Delivery system 410, having apparatus 450disposed therein, is endovascularly advanced, preferably in a retrogradefashion, through a patient's aorta A to the patient's diseased aorticvalve AV. Sheath 420 is positioned such that its distal end is disposedwithin left ventricle LV of the patient's heart H. As described withrespect to FIGS. 35, apparatus 450 is deployed from lumen 422 of sheath420, for example, under fluoroscopic guidance, such that skirt section474 is disposed within left ventricle LV, body section 476 b is disposedacross the patient's native valve leaflets L, and lip section 472 isdisposed within the patient's aorta A. Advantageously, apparatus 450 maybe dynamically repositioned to obtain proper alignment with theanatomical landmarks. Furthermore, apparatus 450 may be retracted withinlumen 422 of sheath 420 via wires 424, even after anchor 470 hasdynamically expanded to the partially deployed configuration, forexample, to abort the procedure or to reposition sheath 420.

Once properly positioned, wires 424 a are retracted to expand skirtregion 474 of anchor 470 within left ventricle LV. Skirt region 474 islocked in the expanded configuration via skirt lock 490, as previouslydescribed with respect to FIGS. 36. In FIG. 38A, skirt region 474 ismaneuvered such that it engages the patient's valve annulus An and/ornative valve leaflets L, thereby providing positive registration ofapparatus 450 relative to the anatomical landmarks.

Wires 424 b are then actuated external to the patient in order to expandlip region 472, as previously described in FIGS. 35. Lip region 472 islocked in the expanded configuration via lip lock 480. Advantageously,deployment of apparatus 450 is fully reversible until lip lock 480and/or skirt lock 490 has been actuated. Wires 424 are pulled fromeyelets 483 and 493, and delivery system 410 is removed from thepatient. As will be apparent, the order of expansion of lip region 472and skirt region 474 may be reversed, concurrent, etc.

As seen in FIG. 38B, lip region 472 engages the patient's native valveleaflets L, thereby providing additional positive registration andreducing a risk of lip region 472 blocking the patient's coronary ostia0. FIG. 38C illustrates the same in cross-sectional view, while alsoshowing the position of replacement valve 460. The patient's nativeleaflets are engaged and/or captured between lip region 472 and skirtregion 474. Advantageously, lip region 472 precludes distal migration ofapparatus 450, while skirt region 474 precludes proximal migration. Itis expected that lip region 472 and skirt region 474 also will reduceparavalvular regurgitation.

What is claimed:
 1. A repositionable prosthetic heart valve, comprising:an expandable stent having an elongated configuration, an expandedconfiguration, and a repositionable configuration; wherein the stent isdesigned to shift between the elongated configuration and the expandedconfiguration; wherein the stent is designed to shift between theexpanded configuration and the repositionable configuration so that thestent can be repositioned after being expanded; wherein the stent isdesigned to shift between the elongated configuration and therepositionable configuration; and a plurality of leaflets coupled to thestent.
 2. The repositionable prosthetic heart valve of claim 1, whereinthe stent includes a self-expanding material.
 3. The repositionableprosthetic heart valve of claim 1, wherein the stent includes anickel-titanium alloy.
 4. The repositionable prosthetic heart valve ofclaim 1, wherein the stent includes a cobalt-chromium alloy.
 5. Therepositionable prosthetic heart valve of claim 1, further comprising asealing member coupled to the stent.
 6. The repositionable prostheticheart valve of claim 5, wherein at least a portion of the sealing memberis disposed along an outer surface of the stent.
 7. The repositionableprosthetic heart valve of claim 5, wherein the sealing member includes afabric.
 8. The repositionable prosthetic heart valve of claim 5, whereinthe sealing member includes a pocket.
 9. The repositionable prostheticheart valve of claim 5, wherein the sealing member includes a sac. 10.The repositionable prosthetic heart valve of claim 1, wherein the stentis partially expanded while in the repositionable configuration.
 11. Therepositionable prosthetic heart valve of claim 1, wherein the stent hasan inflow end region and an outflow end region, and wherein the inflowend region, the outflow end region, or both are flared.
 12. Arepositionable prosthetic heart valve, comprising: an expandable stenthaving a delivery configuration, a repositionable configuration, and adeployed configuration; a plurality of leaflets coupled to the stent;and a sealing member coupled to the stent.
 13. The repositionableprosthetic heart valve of claim 12, wherein the stent includes anickel-titanium alloy.
 14. The repositionable prosthetic heart valve ofclaim 12, wherein the stent includes a cobalt-chromium alloy.
 15. Therepositionable prosthetic heart valve of claim 12, wherein at least aportion of the sealing member is disposed along an outer surface of thestent.
 16. The repositionable prosthetic heart valve of claim 12,wherein the sealing member includes a fabric.
 17. The repositionableprosthetic heart valve of claim 12, wherein the sealing member includesa pocket.
 18. The repositionable prosthetic heart valve of claim 12,wherein the sealing member includes a sac.
 19. A method for positioninga prosthetic heart valve, the method comprising: advancing a prostheticheart valve to a position adjacent to a native heart valve; shifting theprosthetic heart valve from a delivery configuration to a repositionableconfiguration; translating the prosthetic heart valve relative to thenative heart valve while the prosthetic heart valve is in therepositionable configuration; and shifting the prosthetic heart valvefrom the repositionable configuration to a deployed configuration. 20.The method of claim 19, further comprising shifting the prosthetic heartvalve from the deployed configuration to the repositionableconfiguration.